Research on the photoluminescence properties and stability of Cu2+-doped perovskite CsPbCl1.5Br1.5 quantum dots

Cu:CsPbCl_xBr_3-x quantum dots (QDs) with different Cu-to-Pb molar ratios were synthesized via a solvent-based thermal synthesis method, and highly stable blue-light PCL@Cu:CsPbCl_xBr_3-x composite fibers (CFs) were prepared by electrohydrodynamic (EHD) technology. The photoluminescence (PL) properties of these Cu²⁺-doped Cu:CsPbCl_xBr_3-x QDs and the stability of polymer encapsulation were investigated in this study. The results showed that with increasing Cu²⁺ concentration, the CsPbCl_1.5Br_1.5 QDs maintained their initial cubic crystal structure. The doping of Cu²⁺ ions effectively eliminated the surface defects of CsPbCl_1.5Br_1.5 QDs, facilitating excitonic recombination through radiative pathways. The PL quantum yield (PLQY) of Cu:CsPbCl_1.5Br_1.5 QDs increased to 85%. In addition, The fiber encapsulation method effectively improved the stability of the Cu:CsPbCl_1.5Br_1.5 QDs, After 3 days in water, the fluorescence intensity still remains at the initial 90%. Based on these results, it is believed that Cu:CsPbCl_1.5Br_1.5 QDs have promising applications in optoelectronic devices in the future.